As work on a new album began, the members of No Bird Sing decided to go out on a limb. After stripping the band bare on 2011's Theft of the Commons, recorded live in a barn, the Minneapolis hip-hop trio went in the opposite direction. For almost two years, they dove headlong into the studio in search of reinvention. In the process, they dug deep inside themselves.

"It meant me sitting in the dark by myself — just sitting there until thoughts popped up that scared me," says vocalist Joe Horton with a laugh. "I'd sit and look at them until I wasn't afraid of them anymore." He holds out his cupped hands as though to imitate a lotus pose. "Then when I sat down to write, the two informed each other because I was trying to get past all the fears I have that I don't allow myself to think about."

The resulting record, Definition Sickness, bristles with intense focus. Locked into a murky, underwater groove and Horton's growling flow, it never flinches from the mind's darkest recesses. For a band that's long eschewed what it means to play hip-hop, this is a record that defines their voice more clearly than ever before.

"It's almost like a different band," admits drummer Graham O'Brien. In between records, he and engineer Adam Krinsky built a new recording studio, Bellows, in St. Paul, which not only served as the band's new base but also encouraged them to experiment more. O'Brien's drumming, in particular, helps anchor the band's new, fuller sound. "It's more of a traditional rap album in the sense that, if you sample drums from 10 different bands, they all sound real different," he says. "So we treated the drums like they were samples." They drew on some of their own demos and used them as samples, as well, helping to build a more immersive patchwork.

In turn, the music on Sickness is more abrasive and more melodic than any previous No Bird Sing recordings. That melodicism is no coincidence, either. It's helped not only by guitarist Bobby Mulrennan's typically fluid tones, but also by the addition of some strings, keys, and backup singers — including the likes of Chastity Brown, Aby Wolf, and Molly Dean. Plus, there are guest verses by rapper friends Kristoff Krane and Horton's Mixed Blood Majority cohort Crescent Moon.

But the most noteworthy of the guests is Sage Francis. The Providence, Rhode Island-based legend of the rap battle circuit signed No Bird Sing to his Strange Famous label for Sickness and appears on the album's first single, "Don't Think." Horton had initially met Francis at the dedication of a memorial to their mutual friend, Micheal "Eyedea" Larsen.

"We did have a couple options and he said, 'Whether or not you go with me, I got your back,'" says Horton. "A big reason we went with them is that Sage really cares about the music he puts out."

Guest spots aside, what makes Sickness work is the warmth and intimacy that the band captured all on their own. Horton freely admits that his complex raps, often tinged with political rhetoric and philosophy, have at times verged too far toward the abstract. Here, he tackles themes of alienation and communication that aim for the universal but strike deepest on an interpersonal level.

True, opening track "Breathless" kicks things off with a withering societal critique: "My country's got murderer's blood/I don't want to talk about it/Nobody does/So nobody does." But a song like "Heaven and Other Drugs" is devastating for how it weaves together the numbing effects of drugs and religion with the lives of two people paralyzed by their own frailty and jealousy. Either scenario, Horton surmises, amounts to nothing more than "a pile of hollow bones."

Not surprisingly, making a record like Sickness proved a taxing one for the members of No Bird Sing. "It definitely took its toll," concedes Horton. "Each of us, at different points, felt like we were carrying the record on our backs — just bearing all these concepts and things with you at all times." But that doesn't make it any less rewarding — a point that may be best left to the music itself. As Horton says on the hauntingly beautiful "And War," "I've never seen a newborn smile that wasn't worth the pain of labor in the end."